1. Field of the Invention
The present invention generally relates to vacuum devices, and more particularly to vacuum attachments for cleaning floors.
2. Background Information
When vacuum cleaners are used to clean floors, they use either a powered cleaning head which contacts the floor, or a non-powered cleaning head. The powered cleaning heads typically have a separate electrical motor which powers brushes or rollers which mechanically assist the vacuum process in loosening particulates from carpet fibers. These powered heads are by necessity heavier than non-powered heads. They also have the disadvantage of causing a certain degree of physical damage to carpet fibers when they are utilized. In high volume commercial areas such as in hotels, motels, convention centers, and other carpeted commercial areas, daily vacuuming with a powered vacuum head can shorten the life of carpet by the continual breaking of carpet fibers.
What is needed is a non-powered vacuum head which can be used on carpets or non-carpeted flooring, and which is very effective at picking up particulate matter, especially in carpets.
The problem with most non-powered vacuum heads is that they are much less successful at picking up particulates than powered heads. If suction is increased in non-powered heads, they also have the possibility of being sucked down into the carpet fibers, making movement of the vacuum head over a carpet more difficult. Since there is no agitation of the carpet fibers by rollers or beater bars, a non-powered head has to use some other mechanism in order to pick up particulates as effectively as a powered carpet head.
Prior art carpet heads typically lose a significant amount of efficiency due to the design of the vacuum head. Any time that the air flow is required to take a sharp 90xc2x0 turn, a significant amount of efficiency is lost. If the cross sectional surface area of the air bypass openings into the vacuum head is too large, then the air speed through each of these openings is decreased. With decreased air speed, there is less capacity of the air to lift and carry particulates, and less ability for the air to disrupt calm layers of air adjacent to the floor surface. If the number of air bypass channels is reduced, and the cross sectional area of each hole is also reduced, air velocities through the air bypass channels can be increased, but it is possible to have areas of carpet which are uncleaned due to the fewer number and smaller size of air bypass channels.
These disadvantages result in prior art floor cleaning tools which are marginally effective in cleaning carpets or non-carpeted floors. One strategy to solve these problems is to design a tool which encourages laminar flow of air through the tool. The belief is that laminar flow is higher in speed, and thus the air has a greater capacity to carry a load of particulates. Some vacuum tools are designed with goal, and promote laminar air flow. However, in practice pure laminar flow is not effective in picking up particulates. The air flow may be faster, but its directness through the tool may keep it from actually picking up any dirt.
Accordingly, it is an object of the invention to provide an improved floor cleaning tool which is aerodynamically designed for increased efficiency. It is a further object of the invention to provide a design which utilizes the configuration and alignment of the air bypass slots to create vortices inside the vacuum head for improved particulate pickup.
It is a further object of the invention to provide a vacuum cleaning tool which has a region in the vacuum head which produces high-speed laminar flow for particulate pickup, another area which provides for vortex formation, and another area which pulls air and particulates from the vortex region and forms them into a laminar flow air pattern.
It is a further object of the invention to provide an aerodynamically configured top cover, which eliminates 90xc2x0 bends in the air flow. It is a further object of the invention to provide a vacuum tool which has a footprint which provides complete coverage for a section of floor in the path of the vacuum tool.
These and other objects are attained by the floor tool of the invention, which is designed to generate vortices in the cleaning head. The vortex floor tool is a floor tool for use with a vacuum cleaner. It includes a vacuum chamber in which the vortices are formed, and which includes a front side, a rear side, a right side, and a left side. Each of these sides has a bottom portion having a generally flattened floor contacting bottom edge. The bottom portion is designed to have a rounded leading and trailing edge, and a wide contact zone, for making the tool easy to maneuver on carpet under suction. In the bottom edge, a number of air bypass channels are defined. These air bypass channels are generally perpendicular to the side they reside in. These air bypass channels allow air to enter the vacuum chamber from outside the vacuum chamber, in response to the vacuum created by the vacuum means inside the vacuum chamber. The rear side is parallel to the front side, and is held in a spaced apart relationship with the front side by the right and left side. The front and rear side are attached to the right side as well as to the left side. The right side is held in a spaced relationship with the left side. A top cover portion attaches to the top edges of these four sides. In the top cover portion is defined an orifice for connection to a vacuum means, which is typically a vacuum cleaner. With the four sides, the top cover portion forms the vacuum chamber, which is open on the bottom side. The air bypass channels formed in the front side are offset in alignment from the air bypass channels in the rear side, and are thus configured to form multiple vortices in the vacuum chamber. The four sides make up a generally rectangular vacuum chamber, which could also be somewhat oval, elliptical, or rounded in shape and be equivalent to a rectangular shape.
The left side and the right side can also be configured to define one or more bypass channels in each of the left side and the right side. If present, the air bypass channel in the left side and the right side are configured to induce horizontally oriented vortices inside the vacuum chamber. The vacuum cleaner floor tool has a longitudinal axis which extends normal to the front side and the rear side. The lateral axis is normal to the longitudinal axis and also normal to the left side and the right side. The vertical axis is normal with the longitudinal axis and normal to the lateral axis.
In one configuration of the vacuum cleaner floor tool, the top cover includes a curving front cover face which is connected to the front side and extends vertically from the front wall, and curves towards a horizontal plain in the direction of the rear wall. The curving front cover face connects with an orifice in the top cover for receiving a tube from the vacuum means. This configuration of the device also includes a curve in the rear cover face which is connected to the rear wall and extends generally parallel to the curving front cover face. It begins vertically from the rear wall and curves toward the horizontal plain away from the front side and rear side. The curving rear cover face also connects with the tube receiving orifice, which connects to the vacuum means. The device of this configuration also includes a curving right cover face which is connected to the right side of the top cover, and at its edges, connects to the curving front cover face and the curving rear cover face. The curving right cover face curves towards the longitudinal axis of the floor tool, and towards the horizontal plain. It also forms a connection with a tube receiving orifice for the vacuum means. Also included is a curving left cover face which is connected to the left side of the top cover, and at its edges to the curving front cover face and the curving rear cover face. The curving left cover face curves towards the longitudinal axis of the floor tool and towards the horizontal plain. These four curving sides form a laminar flow top cover which forms an aerodynamically unrestricted path for air from the vacuum chamber to the tube receiving orifice. The curving nature of the laminar flow top cover reduces the velocity loss of the air when it makes the required two 90xc2x0 turns through the vacuum cleaner floor tool. The vacuum cleaner floor tool of the above curving configuration can be constructed so that the laminar flow top cover portion covers at least ⅔ of the top cover of the vacuum chamber.
Another aspect of the invention includes a vacuum cleaner floor tool in which the offset air bypass channels are configured to create three separate patterns of air flow. The first pattern of air flow is high velocity and laminar, and occurs where the air passes through the air bypass channels from outside the vacuum chamber, and enters into the vacuum chamber itself. Immediately adjacent to the air bypass channels, the air flow changes to a relatively lower speed, and forms into multiple standing vortices inside the vacuum chamber. The offset position of the air bypass channels causes the air streams from each air bypass channel to reinforce the direction of rotation of adjacent vortices, add to its velocity, and augment it. After passing through the high turbulence of the vortices, air once again enters into laminar flow as it passes into the laminar flow top cover portion and into the tube from the vacuum means.
One configuration of the vacuum cleaner flow tool includes a bottom portion on each of the sides of the vacuum chamber. In cross section, this bottom portion can be semicircular or flat in the middle with curved leading edges with a curved leading edge and curved trailing edge. One configuration of the vacuum cleaner floor tool includes air bypass channels which have a cumulative opening area of 0.7 to 0.9 inches in cross section. In one configuration of the vacuum cleaner floor tool, the air bypass channels are spaced greater than 1 inch apart, and less than 2 inches apart. In another configuration of the floor tool, the air bypass channels in the front side are approximately equal in number, and in total cross sectional area, as the air bypass channels in the rear side. In another version of the vacuum cleaner floor tool, the air bypass channels have a cumulative opening area of 0.75 to 0.875 square inches.
The vacuum cleaner floor tool can also include a floor brush which attaches to the vacuum chamber housing and which brushes the floor surface during use.
In the configuration of the vacuum cleaner floor tool which includes one or more air bypass channels in the left and the right sides, the total cross sectional area of the air bypass channels in the right and left sides totals less than 0.2 square inches.
In one configuration of this device, the air bypass channels in the left and the right side are approximately xe2x85x9 inch in height and ⅝ inch in width. In this configuration of the floor tool, the combined cross sectional are of the left and right air bypass channels makes up 7 to 12% of the cumulative cross sectional area of all bypass slots of the floor tool. In this configuration of the floor tool, the air bypass channels in the front side and rear side are xc2xc inch in width, and have a semicircular top surface.
Still other objects and advantages of the present invention will become readily apparent to those skilled in this art from the following detailed description wherein I have shown and described only the preferred embodiment of the invention, simply by way of illustration of the best mode contemplated by carrying out my invention. As will be realized, the invention is capable of modification in various obvious respects all without departing from the invention. Accordingly, the drawings and description of the preferred embodiment are to be regarded as illustrative in nature, and not as restrictive.